package com.shennan.eduService.listener;

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.shennan.eduService.entity.EduSubject;
import com.shennan.eduService.entity.excel.SubjectData;
import com.shennan.eduService.service.EduSubjectService;

public class SubjectExcelListener extends AnalysisEventListener<SubjectData> {

    //这个类不能交给spring管理，需要自己new，因此无法注入其他对象
    //不能注入service，无法实现数据库操作

    //解决方案，在使用的时候new一个对象，手动注入进来，所以要创建一个有参构造，把service引入
    public EduSubjectService subjectService;

    public SubjectExcelListener(){}

    public SubjectExcelListener(EduSubjectService subjectService){

        this.subjectService = subjectService;
    }



    //读取excel内容，一行一行进行读取
    //SubjectData存放的是从excel读到的内容
    //需要把数据转换成适合数据库的格式
    //先存一级条目到数据库，后存二级条目，有一个连接关系
    @Override
    public void invoke(SubjectData subjectData, AnalysisContext analysisContext) {
        if(subjectData == null) {
            throw new RuntimeException("数据已经读完了");
        }

        //一行一行读取，每次读取有两个值，第一个值一级分类，第二个值二级分类
        //判断一级分类是否重复
        EduSubject existOneSubject = this.existOneSubject(subjectService, subjectData.getOneSubjectName());
        if(existOneSubject == null) { //没有相同一级分类，进行添加
            existOneSubject = new EduSubject();
            existOneSubject.setParentId("0");
            existOneSubject.setTitle(subjectData.getOneSubjectName());//一级分类名称

            subjectService.save(existOneSubject);//存到数据库
        }

        //获取一级分类id值
        String pid = existOneSubject.getId();

        //添加二级分类
        //判断二级分类是否重复
        EduSubject existTwoSubject = this.existTwoSubject(subjectService, subjectData.getTwoSubjectName(), pid);
        if(existTwoSubject == null) {
            existTwoSubject = new EduSubject();
            existTwoSubject.setParentId(pid);
            existTwoSubject.setTitle(subjectData.getTwoSubjectName());//二级分类名称

            subjectService.save(existTwoSubject);//存到数据库
        }
    }

     /*
     * String name 一级分类
     * */
    //查询数据库，判断一级分类不能重复添加
    //为了能查询数据库，把service注入进来
    private EduSubject existOneSubject(EduSubjectService subjectService,String name) {
        QueryWrapper<EduSubject> wrapper = new QueryWrapper<>();    //mybatis ：sql语句
        wrapper.eq("title",name);   //分类名称title=name
        wrapper.eq("parent_id","0");    //parent_id=0
        EduSubject oneSubject = subjectService.getOne(wrapper);
        return oneSubject;
    }

    //查询数据库，判断二级分类不能重复添加
    private EduSubject existTwoSubject(EduSubjectService subjectService,String name,String pid) {
        QueryWrapper<EduSubject> wrapper = new QueryWrapper<>();
        wrapper.eq("title",name);
        wrapper.eq("parent_id",pid);
        EduSubject twoSubject = subjectService.getOne(wrapper);
        return twoSubject;
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {

    }
}
